1. Field of the Invention
The present invention relates to a recording and/or reproducing system.
1. DESCRIPTION OF THE PRIOR ART
In a recording and/or reproducing system, for example a magnetic disc unit such as a floppy disc unit for performing recording and/or reproducing on a magnetic recording medium such as a floppy disc, a holder for containing a cassette containing a magnetic disc is disposed. In many arrangements, this holder is lowered automatically when the cassette is inserted as far as a first predetermined position inside the unit so that the cassette is loaded in a second predetermined position where recording and/or reproducing is performed on and/or from the disc.
In this type of conventional system, however, when the direction of insertion of the cassette is a first direction, the holder is lowered in a second direction which intersects at right angles with the first direction so that when the cassette is inserted into the holder through an opening on a front panel, an operator had to push with fingertips a back edge of the cassette inside the opening on the front panel so that the cassette is positioned at the first predetermined position. Consequently, the cassette loading operations were troublesome, and often faults arose easily.
Moreover, a conventional apparatus for performing cassette loading and ejection has many levers and slide members. Loading and ejection operations are performed by sequential movement of these levers and slide members so that even a small discrepancy in a timing of the sequential movement prevents loading and ejection operation, causing a high rate of faults. Furthermore, the large number of parts means a large number of assembling steps which produces the disadvantage of increasing the cost of the product.
Moreover, a magnetic disc unit for handling a cassette having an opening (head window) that exposes a part of a disc and an opening and closing member (shutter) that allows for opening and closing of the head window has a member for releasing the head window by acting on an edge of the shutter when the cassette is being loaded. Conventional arrangements have a pin-shaped cylindrical member as this member.
In this type of conventional magnetic disc unit, however, when a diameter of this pin is small, it sometimes becomes impossible to perform the ejection because this pin gets stuck between the cassette housing and the edge of the shutter when the cassette is being ejected. On the other hand, when the diameter of this pin is too large the linkage with the edge of the shutter is not performed adequately, so that faults such as improper opening occur.
Commonly, however, a flat spring is disposed on the holder so that the cassette is held pressingly at a predetermined position inside the holder such as an inside bottom surface of the holder. In a conventional magnetic disc unit, this flat spring was attached to the holder by forcing a joining member such as a rivet into an eyelet, or by a joining member such as a screw.
This type of joining member, however, offered poor workability when being attached, and resulted in high assembling costs.
In a magnetic disc unit such as described above, the magnetic head for recording and/or reproducing must move along the surface of the magnetic disc while maintaining a precision attitude in a left-to-right and up-and-down direction.
In a conventional arrangement, a fixed carriage guide shaft was disposed with respect to a head carriage that mounted a head. The carriage has a plurality, for example two hole-shaped slider portions into each of which a bushing is fitted. The guide shaft is inserted through these bushings.
This arrangement required, however, that the carriage slider portions, that is the holes in which the bushings are fitted, be formed with a high degree of accuracy so as to align. Consequently, the arrangement involved high working costs. Furthermore, if there was any discrepancy in the alignment, it was not possible to adjust this later so that there was the disadvantage that a high degree of accuracy was required from the first.
This disadvantage was not limited, of course, to a magnetic disc unit, but was also encountered in other recording systems such as a system for recording and/or reproducing on and/or from an optical disc or a printer having a mechanism for moving a print head.
The carriage guide shafts are attached to a chassis base plate of the unit. In the conventional arrangement, this attachment was performed by pressing the guide shafts into a positioning notch formed on the chassis base plate by a free edge of a leaf spring whose one other end was fixed to the base plate by a screw.
Consequently, in a conventional magnetic disc unit the operations for attaching guide shafts were extremely troublesome, and had the disadvantages of poor workability and high working costs.
These disadvantages were not limited, of course, to magnetic disc units, but were also encountered on other recording and/or reproducing systems and on printers having a head carriage mechanism.
When, however, travel of the head carriage described above was performed by, for example, a lead screw driven by a stepping motor, adjustment of the motor and the screw attachment position was necessary in order to guarantee the travel position accuracy of the magnetic head on the magnetic disc, that is the track accuracy. Furthermore, in other cases such as when a photo-coupler performs detection of a position corresponding to a standard position of the head or head carriage, for example track number "0" on the magnetic disc, adjustment of the attachment position of the detector is also necessary.
In conventional arrangements, adjustment of the position of this type of unit has been performed by a metallic eccentric screw or eccentric pin attached to the chassis base plate. Attachment of the eccentric screw or eccentric pin to the base plate was troublesome, however, particulary in the case of an eccentric pin which had to be attached to the base plate by tightening in a rotatable manner to allow for adjustment, thereby further diminishing the workability.
This tendency was not limited, of course, to units such as motors, screws or detectors, but was also encountered when adjusting the positions of various other members requiring such adjustment.
Recording and/or reproducing systems such as magnetic disc units, however, as well as other apparatuses have various detection switches and operating switches. In general, these types of switches have a switch contact arm, an operating member for operating that switch contact arm and a supporting member mounted on a base plate for supporting that operating member.
In conventional switch arrangements, however, when a switch mechanism was assembled on a base plate, an assembling step of fitting the supporting member into a hole formed on the base plate was performed, thereby diminishing workability and increasing working costs.
Normally, a plurality of switches such as detection switches and operating switches are disposed. In such cases, conventional arrangements often involved mounting each of this plurality of switches completely independently. This, however, increased the number of parts and had the disadvantages of poor workability of assembling operations and higher working costs.
Generally, however, in electronic apparatuses having a motor to provide drive, a yoke plate of the motor (for example, a stator yoke plate on a brushless motor) is attached to the chassis base plate. If we consider, for example, a motor for driving a magnetic disc in a magnetic disc unit, when a flat brushless motor is used the stator yoke plate is sometimes attached to the chassis base plate with studs and sometimes without studs.
This arrangement, however, makes it difficult to keep the overall apparatus thin and light, and also prevents cost reductions because of the number of parts involved.